I have used these tees for about 2-3 weeks. I originally bought them for using in my indoor golf simulator, with a SkyTrak Launch Monitor. The #1 and #2 tees work just fine if you are perhaps trying to tee up a long iron or hybrid ever so slightly. The larger ones that you would use for a driver cause a lot of miss-reads by the skytrak.

https://www.amazon.com/BirTee-Pro-Winter-Golf-Tees/dp/B00RXQ2I8G